Synthesis and Characterization of Mono- and Bi-iron Chalcogeno-ferrocenylcarboxylato Complexes

Chalcogenocarboxylato complexes of iron bearing ferrocenyl moieties having two iron atoms in different electronic environments have been synthesized and characterized. Synthesis is accomplished by reactions of (μ-Ex)[CpFe(CO)2]2 (E= S, x= 2-4; E= Se, x= 1) with ferrocenoyl chloride (ClCOC4H5)FeCp which generated CpFe(CO)2ECOC5H4FeCp (E= S (1), Se (2)) in good isolated yields. The analogous reaction with bi-functional ferrocene dicarbonyl dichloride (ClCOC4H5)2Fe gave both the mono substituted products CpFe(CO)2ECOC5H4Fe(C5H4COOH) (E= S (3), Se (4)) or the di-substituted species [CpFe(CO)2ECOC5H4]2Fe (E= S (5), Se (6)). The authentication details of complexes 1-6 are presented along with the results from infrared, ultraviolet-visible, proton and carbon-13 nuclear magnetic resonance spectroscopies. In addition, the structures of 2, 3 and 4 were determined by single crystal X-ray diffraction, evidencing both the half-sandwich and sandwich geometries of the two iron centers.